There are several known gas transmission measuring devices available and in fairly extensive employment on and in the market. Prominent and widespread in application amongst these are The Dow Gas Transmission Cell (ASTM Designation D-1434-66T) available from Custom Scientific Instruments, Inc. of Whippany, N.J. 07981 and the Linde Permeability Cell (ASTM Designation D1434), also available from the same mentioned commercial source.
The available gear for the indicated purpose, including those above specifically identified, generally require a constant pressure drop and temperature in order to obtain the desired permeation data. These requirements, as is well comprehended by those skilled in the art, impose some disadvantageous limitations and disabilities on the known apparatus and uses thereof.
Thus, for indicated testing purposes, nothing in prior art appears to realistically concern itself with a truly dynamic way of measuring the transmission rate of various gases through curved or flat plastic sheets, liners, films, etc. in the same efficient and extremely reliable manner, well-adapted for commercial testings and investigations, in the style and means of implementation as is so crucially indigenous as is present and involved in the instant contribution to the art.